1. Field of the Invention
The present invention relates to a mobile radio communication apparatus such as a portable telephone and a mobile satellite communication terminal.
2. Description of the Related Art
A mobile radio communication apparatus is usually powered by a battery, and accordingly, in order to increase a time period of operation per one battery, the reduction of the power dissipation is an important issue.
In a prior art mobile radio communication system where two mobile stations communicate with each other, when an intensity of a received signal is large, it is considered that the distance between the two mobile stations is small or the transmission state is good, so that the transmission power is decreased (see JP-A-6-13955). Thus, the transmission power of the radio wave signals transmitted between the mobile stations and can always be minimum, which decreases the power dissipation. This will be explained later in detail.
In the prior art mobile radio communication system, however, in order to decrease the power dissipation, if each of the mobile stations has a burst function for intermittently transmitting signals only when significant transmitting data occurs, the power dissipation is rather increased. That is, even when one of the mobile stations and stops transmitting of signals due to the absence of effective transmitting data, the transmission power control section of the other mobile station continues to increase the transmission power of signals. As a result, the power dissipation is rather increased.
In addition, if each of the mobile stations is a mobile satellite terminal, the antenna of each of the mobile stations should be directed to a satellite. Therefore, when the direction of the antenna of one of the mobile stations is deviated from the satellite, the direction of the antenna should be corrected, however, in the prior art mobile radio communication system, the other mobile station continues to increase the transmission power of signals, which also increases the power dissipation.